Manufacture and use of vat dyes of the benzanthrone series



Patented Mar. 8, 1932 UNITEDstares- O lcE ARNOLD-SHEPHERDSON AND SIDNEY THoRNL-EY; oncnmcxnny, MANCHESTER, i I ENGLAND, AssIGNoRs T BRITISH DYESTUFFS CORPORATION LIMITED, OFMAN- CHESTER, ENGLAND MANUFACTURE AND use or VAT DYns on T E nENzA rnnoNn SERIES No Drawing. Application filed July ilhis invention relatesto a new method ofohtaining valuable grey black at dyes. lira patent to; Kunz 1,4:64,079, August 7, 1923, there is described the production of certain vat dyes by acting upon dibenz'an throne with hydrox'ylainine in the presence of sulphuric acid and ferrous sulphate.

s havenow made the surprising dis;

covery thatloy acting upon benzanthrone and its unsulphona-ted derivatives, with hydroxylamine or saltsthereofunder similar conditions, and fusing the intermediate product thus obtained with caustic alkali, new vat dyes are also obtained.

The following examplesillustrate, without limiting, our invention, the parts being by Example I 20 parts of benzanthrone are dissolved with stirring in 400 parts of sulphuric acid of 66 Be. 24 parts of ferrous sulphate crystals are now added, followed, after cooling, by the gradual addition'of 15 parts of hydroxylamine hydrochloride. The whole is now heated to C. and maintained at this temperature for 4 hours. The ferrous sulphate catalyzes and hastens the actions desired." These actions will take place in its absence but a longer period of heating is required. After the heating operation, the reaction mixture is cooled and poured into 1325 parts of ice j raised to 240 C. The melt is maintained at The cooled melt is eX- 240 C. for l'hour. tracted with 1000 parts of water, heated to boiling, and oxidized with a current of air. The dyestuif is filtered off, boiled with dilute hydrochloric acid, washed with water, and

' dried. Itdyes cotton from ahydrosulphite rat in bluish-grey to bluish-black shades. It

dissolves in pyridine giving a bluish green solution. In concentrated sulphuric acid it yields a grayish mauve solution whichon ades, 192?, serial No.12oa17s, and m i Renewed September 17, 1931.

parts 'of-ferrous sulphate crystals are'now free from acid and dried.

Great Britain August 26,1926.

ditionof formaldehyde turns brownerand on addition of a little sodium nitrite remains W p Ea p ze [I 8.5. pyrtsof 'methyl benzanthro-ne, melting point 199, C., prepared from ,B-methyl-anthraquinone, are dissolved. with stirring in parts of sulphuric acid of 66 B. 10.2

added, followed,'after cooling, by the grad 6 ual addition of 6.4 parts of hydroxylamine hydrochloride. The whole is now heated to, 150 C. and maintained at this temperature for 4 hours. Afterwards it is cooled and poured into 565 parts of. ice and water, the wholefbeing then stirred for one hour. The precipitated product is, separated by filtra- I tion, extr ac ted twice, with1000 parts of boiling water and dried. Q 1 1.1 parts of the dried residue are gradually added at C. to 110 parts of stirred. molten caustic potash. The temperature is Slowly raised to 240 C. The melt is maintained at 2a0,C .ffor 2h0urs. The cooled melt is extracted with 1000 parts of water, heated to: boiling and oxidized with a current of air. The dy'estufi'f'is filtered off and washed with water. 7 Finally it is boiled with dilute hydrochloric acid, filtered, washed It dyes cotton from a hydrosulphite rat. in grey to black shades.

WVhat we claim and desire to secure by LettersPatentisi- 1. In the manufacture of new vatdyes, the

process which comprises condensing an unsulphonatedhenzanthrone with a saltofhye droxylam'ine,,. fusing the condensation product withalkali and reco-verlngthe vat dye th s b a he c I Int-he"manufacture of new vat-- .dyes,

the process which comprlses condensing ,be'n-q 5 zanthrone with a salt of hydroxylamine, fusing the condensation product with alkali and recovering the Vat dye thus obtained.

4. In .the manufacture of new vat dyes,

the process which comprises condensing benzanthrone with a salt of hydroxylamine in the presence of ferrous sulphate, fusing the condensation product with alkali and re-' covering the vat dye thus obtained. 5. In the manufacture of new vat dyes, the process which comprises condensing benzanthrone with h'ydroxylamine hydrochloride in the presence of ferrous sulphate, fusing the condensation product with caustic potash and recovering the vat dye thus obtained.

. 6. As a new. article of manufacture,- the product obtained by the condensation of unsulphonated benzanthrones with a hydroxylamine compound of the class consisting of go hydroxylamine and salts of hydroxylamine,

followed by alkaline fusion of the compound so obtained, this product being a "at dye, which with pyridine gives atbluish violet to bluish green solution, which dissolves in con- '26 centrated acid givinga grayish mauve color which color becomes browner on addition of formaldehyde and is unaffected by the addition of a little sodium nitrite and which dyes cotton from a hydrosulphite vat in gray to black shades. r

7. As anew article of manufacture the vat dye obtainableaccording to claim 5, the said vat dyebeing a black powder, soluble in pyridine to a bluish green solution, soluble 3 in concentrated sulphuric acid to' a ayish mauve solution which on addition of ormaldehyde becomes browner and is not affected by the addition .of a small quantity of so dium nitrite and which dyes cotton from a hydrosulphite black bluish gray to bluish b ack shades. i i

' 8. The process of claim 1 in which the by droxylamme (compound is hydroxylamine.

'9. In the manufacture of new dyes, the :process which comprises condensing an unsulphonated benzant hrone compound of the class'consisting of benz'anthrone and alkylbenzanthrone with a hydroxylamine compoundof the class consisting of hydroxylaminc and hydroxylamine hydrochloride, said condensation being effected in the presencev of sulphuric acid, fusing the productthus obtained with caustic potash and recovering the dye thus produced.

10 The processof claim 9 in which the unsulphonated benzanthrone compound is methylbenzanthrone. i f

11. the manufacture of new dyes, the process which comprises dissolving an un- 00 sulphonated benzanthrone compound of the class consisting of benzanthrone and methylbenzanthrone, in sulphuricacid of'66 B. strength, gradually adding hydroxylaininc hydrochloride to the mixture, heating said ll mixture to efiect reaction between said -ben- .a current of ,air, and then isolating, purifying and drying the precipitated dyestufl' thus obtained.

-12. T he process of claim '11 in which the unsuiphonated benzanthrone compound is 'benzanthrone.

"13. The process of claim 11 in which the unsulphonated benzanthrone compound is methylbenzanthrone,

14. As a new article of manufacture the vat dye obtainable from methylbenzanthrone according to the process of claim 11, the said vat dyestuif dyeing cotton from the hydrosulphite vat in gray to black shades.

In testimony whereof we aflix our signatures.

ARNOLD SHEPHERDSON. SIDNEY THORNLEY. 

